Wafer level embedded heat spreader

ABSTRACT

Disclosed herein are a device having an embedded heat spreader and method for forming the same. A carrier substrate may comprise a carrier, an adhesive layer, a base film layer, and a seed layer. A patterned mask is formed with a heat spreader opening and via openings. Vias and a heat spreader may be formed in the pattern mask openings at the same time using a plating process and a die attached to the head spreader by a die attachment layer. A molding compound is applied over the die and heat spreader so that the heat spreader is disposed at the second side of the molded substrate. A first RDL may have a plurality of mounting pads and a plurality of conductive lines is formed on the molded substrate, the mounting pads may have a bond pitch greater than the bond pitch of the die contact pads.

PRIORITY CLAIM AND CROSS-REFERENCE

This application is a divisional of U.S. application Ser. No.13/623,474, filed on Sep. 20, 2012 and entitled “Wafer Level EmbeddedHeat Spreader,” which application is hereby incorporated by referenceherein in its entirety.

BACKGROUND

Generally, one of the driving factors in the design of modernelectronics is the amount of computing power and storage that can beshoehorned into a given space. The well-known Moore's law states thatthe number of transistors on a given device will roughly double everyeighteen months. In order to compress more processing power into eversmaller packages, transistor sizes have been reduced to the point wherethe ability to further shrink transistor sizes has been limited by thephysical properties of the materials and processes. Furthermore, the useof more powerful processors in ever-shrinking package form factors leadsto a thermal management issue. Increased device operating speeds, alongwith a greater transistor count on individual components, create heat inamounts that may damage or reduce the efficiency of the components.Furthermore, tighter package integration and more compact device bringmore heat generating devices into smaller areas, concentrating the heatgenerated.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present embodiments, and thetechniques involved in making and using the same, reference is now madeto the following descriptions taken in conjunction with the accompanyingdrawings, in which:

FIGS. 1-7 are cross-sectional diagrams illustrating intermediate stepsin an embodiment of a method for forming an embedded heat spreader;

FIG. 8 is a cross-sectional diagram illustrating a molded substrate withheat spreader assembly;

FIGS. 9-10 are cross sectional diagrams of embodiments of a wafer leveldevice with embedded heat spreader; and

FIG. 11 is a flow chart illustrating a method for forming a wafer levelassembly having an embedded heat spreader.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to illustrate the relevant aspects of the embodiments and are notnecessarily drawn to scale. For clarity non-essential reference numbersare left out of individual figures where possible.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the present embodiments are discussed in detailbelow. It should be appreciated, however, that the present disclosureprovides many applicable concepts that can be embodied in a wide varietyof specific contexts. The specific embodiments discussed are merelyillustrative of specific ways to make and use the disclosed subjectmatter, and do not limit the scope of the different embodiments.

Embodiments will be described with respect to a specific context, namelymaking and using embedded heat spreaders useful in, for example, waferlevel processor assemblies. Other embodiments may also be applied,however, to other electrical components, including, but not limited to,memory assemblies, displays, input assemblies, discrete components,power supplies or regulators or any other embedded components.

The presented disclosure is directed to providing a system and methodfor creating an embedded heat spreader for an active device, embeddedprocessor, die, chip, discrete component or the like. An embedded heatspreader may permit a heat generating component to dissipate heat ortransfer heat from the component, reducing the heat load on thecomponent, particularly under prolonged use. Providing a heat spreaderfor an embedded die may permit greater die reliability and longer dielife.

Referring to FIG. 1, a cross-section of an embodiment of an intermediatestep for forming a wafer level embedded heat spreader is depicted. Acarrier substrate 102 may comprise a carrier 110 that may be configuredto provide structural rigidity or a base for deposition of subsequentnon-rigid layers. In one embodiment, the carrier 110 may be a glasscarrier, but may alternatively be a wafer, semiconductor, metal,synthetic or other material having a suitable topography and structuralrigidity.

A glue or adhesive layer 108 may, in some embodiments, be applied to thecarrier 110, with an optional base film layer 106 and optional seedlayer 104 applied over the adhesive layer 108. In one embodiment, theadhesive layer 108 may be adhesive tape, or alternatively, may be a glueor epoxy applied to the carrier 110 via a spin-on process, or the like.In some embodiments, the adhesive layer 108 may be used to separate thecarrier 110 from the heat spreader assembly and associated devices orlayers in subsequent steps.

The seed layer 104 may be formed over the adhesive layer 108 and may actas a base for subsequent metal plating or deposition steps. In someembodiments, the seed layer 104 may be used as an electrode in asubsequent electroplating process. The seed layer 104 may be depositedvia physical vapor deposition (PVD), chemical vapor deposition (CVD),including, but not limited to Plasma enhanced CVD (PECVD), low pressureCVD (LPCVD), Atomic layer CVD, via atomic layer deposition, sputtering,electrochemical deposition, or another suitable method. In someembodiments, the seed layer 104 may be copper, and in other embodiments,the seed layer may be gold, aluminum tantalum, nickel, alloys of thesame, or another material or alloy.

The base film layer 106 may, in some embodiments, be applied and formedof a material that advantageously permits later layers to properly form.For example, in one non-limiting embodiment, the base film layer 106 maybe formed of a polymer such as polybenzoxazole (PBO). In such anembodiment, the PBO may be applied to the adhesive layer 108, whereused, or optionally, applied directly to the carrier 110 via spincoating, or the like. A curable polymer such as PBO permits applicationof the base film layer 106 through a spin coating process, but is stillcapable of forming a substantially firm base film through curing.Additionally, PBO may be advantageous because the flexible structurecreated after curing acts as a buffer between materials with differentcoefficients of expansion (CoE). For example, in one embodiment, thecarrier 110 may be glass, and have a CoE much lower than a seed layer104 made, from, for example, copper. In such an embodiment, a semi-rigidbase film layer 106 may act to buffer the different expansions curingthermal processing. However, any suitable material may be used as thebase film layer 106.

FIG. 2 depicts a cross-sectional view of an embodiment of anintermediate step for forming a wafer level embedded heat spreader. Amask layer 112 may be applied over the seed layer 104. In someembodiments, the mask layer 112 may be a photoresist applied via aspin-on process. In other embodiments, the mask layer 112 may be a hardmask such as a nitride, oxide, oxynitride or the like. A mask layer 112that is a hard mask may be applied by PVD, CVD, or via another suitabledeposition method.

FIG. 3 depicts a cross-sectional view of an embodiment of anintermediate step for forming a wafer level embedded heat spreader usinga patterned mask 114. The mask layer 112 is patterned and developed toform the patterned mask 114. The mask layer 112 may be patterned to formpatterned mask 114 having a heat spreader opening 118 and optionally,one or more via openings 116. In one embodiment, the patterned mask maybe formed so that the structures created in the via openings 116 may beinitially formed to a height of about 105 μm, then subsequently ground,polished, etched, or otherwise reduced to height of about 80 μm to about90 μm. In some embodiments, the via openings 116 in the patterned mask114 may have a pitch of around 110 μm and diameter of about 70 μm. Thusthe structures formed in the via openings 116 will have a resultingheight-to-width ratio of 1.5:1 after formation.

FIG. 4 depicts a cross-sectional view of formation of the heat spreader120 according to some embodiments of the disclosure. In one embodiment,the heat spreader 120 may be deposited via a plating process such as athrough-aperture-via (TAV) plating process. In some embodiments, theheat spreader 120 may be formed in the same step as one or more vias122. For example, one non-limiting embodiment may be where copper isplated on the seed layer 104 to fill the via openings 116 and the lowerportion of the heat spreader opening 118 to form the vias 122 and heatspreader 120, respectively. This may be accomplished, for example, by acopper electroplating process where the carrier substrate 102 with thepatterned mask 114 applied is submerged in a copper solution with acurrent applied, resulting in buildup of copper on the seed layer 104.Alternatively, an electroless plating process, CVD, PECVD or anothermetal deposition process may be employed to form the heat spreader 120and vias 122. The thickness of the heat spreader 120 may depend on thearea of the heat spreader 120 and the number of vias 122. For example,in some embodiments, there may be 1200 vias 122, and the heat spreader120 may be formed to a thickness between about 3 μm and about 5 μm.

While the process for forming the heat spreader 120 and via 122 may takeplace using a plating process and at the same time, in anotherembodiment, forming the heat spreader 120 and any vias 122 may beperformed in multiple steps. For example, the vias 122 may be formed ina first plating step, and then the heat spreader 120 formed or placed ina subsequent step. In such an embodiment, the patterned mask 114 may beformed without the heat spreader opening 118, but with the via openings116. The vias 122 may be formed in the via openings 116, and the heatspreader opening 118 may be formed after the vias 122 are formed. Theheat spreader 120 may then be formed in the heat spreader opening 118after the vias 122 are already formed. In such an embodiment, the vias122 may be masked or covered during the formation of the heat spreader120. A multi-step metal deposition procedure may permit application ofdifferent materials for the vias 122 and heat spreader 120. For example,a copper heat spreader 120 may be formed after vias 122 formed from, forexample, gold, are created.

The embedded heat spreader 120 may also, in another embodiment, beformed separately, and then applied to the carrier substrate 102. Insuch an embodiment, the heat spreader 120 may, for example, be milled,molded or otherwise formed away from the carrier substrate 102, and thenapplied to the adhesive layer 108, the base film layer 106, or the seedlayer 104. In such an embodiment, the seed layer 104, which may not berequired or advantageous since the heat spreader 120 is being placedinstead of formed in situ, may be eliminated, and the heat spreader 120applied to the base film layer 106, adhesive layer 108, or to thecarrier 110 directly.

FIG. 5 depicts a cross-sectional view of application of an active devicesuch as a die 130 to the heat spreader 120 according to some embodimentsof the disclosure. The patterned mask 114 is removed after formation ofthe vias 122 and heat spreader 120. For example, in embodiments wherethe mask layer 112 was formed by a photoresist, the resulting patternedmask 114 may be removed via ashing and an optional rinse or cleaning. Inembodiments where the mask layer 112 was formed by a hard mask, theresulting patterned mask 114 may be removed by etching the pattern maskto leave the underlying carrier substrate 102.

A die 130 is applied to the heat spreader using a die attachment layer132 such as a die attachment film (DAF) or the like. In someembodiments, the die attachment layer 132 may have thermalcharacteristics sufficient to bring the die 130 into thermal contactwith the heat spreader 120. In some embodiments, the die attachmentlayer 132 may be a thermal compound having, for example, a silvercontent sufficient to transfer an amount of heat from the die 130 to theheat spreader 120 to permit the die 130 to operate while generating apredetermined heat output. Thus, the die attachment layer 132 maytransmit sufficient heat energy from the die 130 to the heat spreader120, lowering or maintaining the temperature of the die 130 when the dieis operating within a predetermined range. Such temperature managementmay permit the die 130 to operate at a higher speed or capacity forlonger periods of time while maintaining the integrity of the die 130components.

In some embodiments, the die 130 may be attached to the heat spreader120 by attaching the top, or non-contact, side of the die 130 to theheat spreader 120 by the die attachment layer 132. Thus, the die 130 maybe placed so that a first side of the die 130 having one or more contactpads 131 or mounting pads of the die 130 is opposite a second side ofthe die 130 that is mounted to the heat spreader 120.

FIG. 6 depicts a cross-sectional view of application of a moldingcompound 134 to embed the heat spreader 120. The molding compound 134may be a flowable compound having a high dielectric constant. In someembodiments, a mold or other enclosure for retaining the moldablecompound may be used to form the molding compound 134. In such anembodiment, an epoxy or similarly liquid molding compound 134 may beeffectively used to form the molded substrate 800. Additionally themolding compound 134 may be cured after application. For example, themolding compound 134 may be an epoxy that uses a catalyst, and curesafter application. Alternatively, the molding compound 134 may be curedthrough application of a catalyst after application, for example, curinga molding compound via ultraviolet exposure, or through exposure to air,or the like.

FIG. 7 illustrates a polished or reduced molding compound 142 accordingto some embodiments of the disclosure. The molding compound 134 mayundergo a grinding step to remove excess material from the die 130contact pads 131 and vias 122. In such an embodiment, the moldingcompound 134 may be subjected to a chemical-mechanical polish, a purelymechanical polish, chemical etching, or another suitable reductionprocess. The resulting reduced molding compound 142 may, in someembodiments, have a top surface at or below the top surfaces of the vias122 and the die 130 contact pads 131. Thus, the vias 122 and die 130contact pads 131 may be exposed at the polished side of the reducedmolding compound 142 such that electrical contacts may be formed on thevias 122 and die 130 contact pads 131. In some embodiments, the grindingmay also reduce the height of the vias 122 to about 80 μm to about 90μm, resulting in a height-to-width ratio between about 1.1:1 and about1.3:1.

FIG. 8 illustrates a molded substrate 800 after debonding from thecarrier substrate 102. The carrier 110 may be separated from the moldedsubstrate 800 at the adhesive layer 108, and any remaining adhesivelayer 108 material, and any base film layer 106 or seed layer 104material may be removed by, for example, etching, polishing or the like.The resulting molded substrate 800 may have the die 130 contact pads 131exposed on a first side and the heat spreader 120 disposed, and exposed,at a second, opposite side.

FIG. 9 depicts a wafer level assembly 900 having an embedded heatspreader 120 according to an embodiment of the disclosure. The moldedsubstrate 800 may have a first redistribution layer (RDL) 901 disposedon one side and one or more second RDLs 902 disposed on an oppositeside. The first RDL 901 may, in some embodiments, have one or moreconductive lines 910 disposed in an intermetal dielectric (IMD) 904, andin electrical contact with contact pads 131 on the die 130. Theconductive lines 910 may be arranged to provide an electrical connectionbetween contact pads 131 on the die 130 and RDL contact pads 906. Theconductive lines 910 may fan out from the die 130 contact pads 131 suchthat the RDL contact pads 906 may have a larger bond pitch than the die130 contact pads 131, and which may be suitable for a ball grid array908 or other package mounting system. While the first RDL 901 isillustrated having conductive lines 910 configured to fan out andprovide an electrical connection between the die 130 contact pads 131and RDL contact pads 906, the first RDL 901 is not limited to suchembodiments. In some embodiments, the first RDL 901 may also haveconductive lines 910 that connect one or more vias 122 to the RDLcontact pads 906. In yet another embodiment, the conductive lines 910may electrically connect, for example, a via 122 to another via 122, toa die 130 contact pad, or to another die or device disposed in themolded substrate 800.

Additionally, an embodiment of a heat spreader 120 formed larger thanthe die 130 is shown. In some embodiments, the heat spreader 120 may besubstantially the same size or footprint as the die 130, resulting in areduced area required to form the heat spreader 120. The heat spreader120 may be substantially larger than the die 130 to provide a greaterheat dissipation or absorption capacity. The heat spreader 120 may beformed as large as allowed by the requirements of via 122 placement andboundaries of the molded substrate 800.

Similarly, the second RDL 902 disposed on the opposite side of themolded substrate 800 from the first RDL 901 may have one or moreconductive lines 910 disposed in an IMD 904 or other dielectricmaterial. The second RDL 902 conductive lines 910 may interconnect thevias 122, or may connect the vias to one or more other devices orelements disposed in, or outside of, the wafer level assembly 900.

In some embodiments, the second RDL 902 may be disposed over the heatspreader 120, and the region over the heat spreader 120 may includeconductive lines 910. Thus, the second RDL 902 may be disposed over aportion of the heat spreader 120, and a portion of a conductive line 910may also be disposed over the heat spreader 120. Such an embodiment maybe employed where components or vias 122 that are disposed on oppositesides of the heat spreader 120 are connected to each other.

Thus, a wafer level assembly 900 having an embedded heat spreader 120may, in some embodiments, be a device comprising a substrate 800, a die130 disposed in the substrate and having contact pads 131 disposed on afirst side of the die 130 and exposed through a first side of thesubstrate 800 and where a heat spreader 120 may further be in thermalcontact with the die 130 and disposed at a second side of the substrate800. Additionally, the heat spreader 120 may be disposed at a secondside of the die 130 and configured to transfer heat from the die 130. Insome embodiments, at least one via 122 may be disposed in the substrate800 and extending from the first side of the substrate 800 to the secondside of the substrate 800.

In some embodiments, a first RDL 901 may be disposed on the first sideof the substrate 800, and may have at a plurality of RDL contact pads906 and at least one conductive line 910 electrically connecting contactpads 131 on the die 130 to the RDL contact pads 906. Furthermore, theRDL contact pads 906 may have a bond pitch greater than the bond pitchof the contact pads 131. A second RDL 902 may also be disposed on thesubstrate 800 opposite the first RDL 901, and may have conductive linesin contact with the vias 122. The second RDL 902 is disposed on and maycover the heat spreader 120. Additionally, a portion of at least oneconductive line 910 may be disposed over the heat spreader 120. In someembodiments, a die attachment layer 132 disposed between, and in contactwith, the second side of the die 130 and the heat spreader 120. The dieattachment layer 132 may optionally be a die attachment film, and maybond the heat spreader 120 and the die 130.

FIG. 10 depicts a wafer level assembly 1000 having an embedded heatspreader 120 according to another embodiment of the disclosure. In someembodiments, the second RDL 902 may be formed to have a heat exposureopening 1002. This may permit greater airflow over the heat spreader120, resulting in more efficient heat radiation, and permitting the heatspreader 120 to shed excess heat into the surrounding or outsideenvironment. In such embodiments, the conductive lines 910 in the secondRDL 902 may be routed around the heat exposure opening 1002. In someembodiments, the heat exposure opening 1002 may be formed during IMD 904creation by, for example, masking the heat exposure opening 1002. Inother embodiments, the heat exposure opening 1002 may be etched orotherwise created over the heat spreader 120 after the IMD 904 iscreated.

In some embodiments, the second RDL 902 may cover only a portion of theheat spreader 120. In other embodiments, the second RDL 902 maycompletely avoid the surface of the heat spreader 120 to expose anentire surface of the heat spreader 120. Thus, a heat spreader 120larger than the die 130 may be formed, with a portion of the second RDL902 covering only a portion of the heat spreader 120, and with a portionof the heat spreader 120 exposed. In such an embodiment, one or moreconductive lines 910 may be routed through the second RDL 902 over theheat spreader 120, allowing the heat spreader 120 to be formed withoutinterfering with the layout of the second RDL 902 conductive lines 910.

FIG. 11 is a flow chart illustrating a method 1100 for forming a waferlevel assembly 900 having an embedded heat spreader 120. A carriersubstrate 102 may be formed by providing a carrier 110 and applying anadhesive layer 108 on the carrier 110 in block 1102. A base film layer106 may optionally be applied on the adhesive layer 108 in block 1104. Aseed layer 104 may optionally be applied on the base film layer 106 inblock 1106. A patterned mask 114 having a heat spreader opening 118 maybe formed on the carrier substrate 102 in block 1108 by applying andpatterning the mask layer 112. A heat spreader 120 and vias 122 may beformed in the patterned mask 114 in block 1110. A die attachment layer132, which may optionally be a die attachment film, may be applied onthe heat spreader 120 in block 1112. A die 130 having a plurality ofcontact pads 131 disposed on a second side of the die 130 may be mountedvia a first side on the die attachment layer 132 in block 1114. Amolding compound 142 may be applied over the die 130 and heat spreader120 to create a molded substrate 800 in block 1116 so that the contactpads 131 of the die 130 are exposed at the first side of the moldedsubstrate 800, and so that the heat spreader 120 is disposed at thesecond side of the molded substrate 800. The carrier 110 may besubsequently debonded from the device 900. The vias 122 and the heatspreader 120 may be formed at the same time using a plating process oranother suitable metal deposition process.

In some embodiments, the wafer level assembly 900 creation method 1100may further comprise forming a first RDL 901 on the first side of themolded substrate 800 in block 1120. The first RDL 901 may have aplurality of RDL contact pads 906 and a plurality of conductive lines910, each conductive line 910 providing an electrical connection betweena mounting pad 906 and a contact pad of the die 130. In additionalembodiments, the RDL contact pads 906 may have a bond pitch greater thanthe bond pitch of the die 130 contact pads 131. A second RDL 902 mayalso be formed on the second side of the molded substrate 800 in block1120 and may cover at least a portion of the heat spreader 120 and haveat least one conductive line 910 in electrical contact with at least onevia 122.

In some embodiments, a method includes forming a patterned mask over acarrier substrate, the patterned mask having a heat spreader opening;forming a heat spreader over the carrier substrate in the heat spreaderopening; removing the patterned mask after forming the heat spreader;mounting a die over the heat spreader, where the die is in thermalcontact with the heat spreader; and applying a molding compound over thedie and over the heat spreader, where the die is proximate a first sideof the molding compound, and where the heat spreader is proximate asecond side of the molding compound.

In some embodiments, a method includes forming a patterned mask layerover a carrier, the patterned mask layer having a first opening with afirst width and a second opening with a second width, the first widthbeing larger than the second width; forming a heat spreader in the firstopening; forming a conductive via in the second opening; removing thepatterned mask layer; attaching a die to the heat spreader; and forminga molding material over the carrier, where the die, the via and the heatspreader are embedded in the molding material.

In some embodiments, a method includes forming a patterned mask over acarrier, the patterned mask having a first opening and a second opening;forming a heat spreader in the first opening; forming a conductive viain the second opening, where the heat spreader has a width larger than awidth of the conductive via, and the heat spreader has a height smallerthan a height of the conductive via; and removing the patterned mask.The method further includes attaching a die to the heat spreader;embedding the die, the conductive via and the heat spreader in a moldingmaterial; forming a first redistribution structure at a first side ofthe molding material; attaching external connectors to contact pads ofthe first redistribution structure; and forming a second redistributionstructure at a second side of the molding material opposing the firstside, where the heat spreader is proximate the second side of themolding material.

Although the present embodiments and their advantages have beendescribed in detail, it should be understood that various changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the disclosure as defined by the appendedclaims. It will be readily understood by those skilled in the art thatmany of the features and functions discussed above can be implementedusing a variety of materials and orders to the processing steps. Forexample, heat spreaders 120 may be virtually any shape, for example, toavoid vias or conform to the boundaries of the molded substrate 800.Heat spreader 120 may also be any heat conductive material, such asceramic or pother non-metallic material, where such material is calledfor. As another example, it will be readily understood by those skilledin the art that many of the steps for creating a wafer level embeddedheat spreader structure may be performed in any advantageous order whileremaining within the scope of the present disclosure.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed, that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present disclosure.Accordingly, the appended claims are intended to include within theirscope such processes, apparatuses, manufacture, compositions of matter,means, methods, or steps.

What is claimed is:
 1. A method comprising: forming a patterned maskover a carrier substrate, the patterned mask having a heat spreaderopening and a via opening; forming a via in the via opening; forming aheat spreader over the carrier substrate in the heat spreader opening,wherein forming the via and forming the heat spreader compriseperforming a plating process to form the via and the heat spreader at asame processing step; removing the patterned mask after forming the heatspreader; mounting a die over the heat spreader, wherein the die is inthermal contact with the heat spreader; and applying a molding compoundover the die and over the heat spreader, wherein the die is proximate afirst side of the molding compound, and wherein the heat spreader isproximate a second side of the molding compound.
 2. The method of claim1, wherein the die is mounted to the heat spreader by a die attachmentfilm.
 3. The method of claim 1, wherein forming the patterned maskcomprises: applying an adhesive layer on a first side of a carrier;applying a base film layer on the adhesive layer; forming a mask layeron the base film layer; and patterning the mask layer to form the viaopening and the heat spreader opening, thereby forming the patternedmask.
 4. The method of claim 3, further comprising reducing a height ofthe via opening and a height of the heat spreader opening after thepatterning.
 5. The method of claim 3, wherein forming the patterned maskfurther comprises forming a seed layer between the base film layer andthe mask layer.
 6. The method of claim 1, further comprising, afterforming the molding compound, forming a first redistribution structureon the first side of the molding compound, the first redistributionstructure having a plurality of contact pads and a plurality ofconductive lines, a first one of the plurality of conductive linesproviding an electrical connection between a first contact pad of theplurality of contact pads and a contact pad of the die.
 7. The method ofclaim 6, further comprising forming a second redistribution structure onthe second side of the molding compound, the second redistributionstructure having at least one conductive line in electrical contact withthe via.
 8. The method of claim 7, further comprising providing anopening in the second redistribution structure exposing at least aportion of the heat spreader.
 9. A method comprising: forming apatterned mask layer over a carrier, the patterned mask layer having afirst opening with a first width and a second opening with a secondwidth, the first width being larger than the second width, each of thefirst opening and the second opening exposing sidewalls of the patternedmask layer; forming a conductive via in the second opening; placing aheat spreader in the first opening; removing the patterned mask layer;attaching a die to the heat spreader; and forming a molding materialover the carrier, wherein the die, the via and the heat spreader areembedded in the molding material.
 10. The method of claim 9, furthercomprising: removing the carrier; and forming a first redistributionstructure at a first side of the molding material, wherein contact padsof the die are exposed at the first side of the molding material, wherethe first redistribution structure is electrically coupled to thecontact pads of the die.
 11. The method of claim 10, further comprisingforming a second redistribution structure at a second side of themolding material opposing the first side of the molding material,wherein the second redistribution structure has an opening that exposesthe heat spreader.
 12. The method of claim 9, wherein the heat spreaderhas a width larger than a width of the die.
 13. The method of claim 9,wherein forming the conductive via and placing the heat spreader areperformed in a same processing step.
 14. The method of claim 9, whereinforming the conductive via and placing the heat spreader are performedin different processing steps.
 15. The method of claim 14, wherein thevia is formed of a first material, and the heat spreader is formed of asecond material different from the first material.
 16. The method ofclaim 14, wherein the heat spreader is pre-formed, and wherein placingthe heat spreader comprises attaching the pre-formed heat spreader tothe carrier substrate.
 17. The method of claim 9, further comprisingforming a redistribution structure over the heat spreader, wherein theredistribution structure is formed to have an opening that exposes atleast a portion of the heat spreader.
 18. The method of claim 9, furthercomprising forming a redistribution structure over the heat spreader,wherein the redistribution structure has a conductive line disposeddirectly over the heat spreader.
 19. A method comprising: forming apatterned mask over a carrier, the patterned mask having a first openingand a second opening; placing a heat spreader in the first opening;forming a conductive via in the second opening, wherein the heatspreader has a width larger than a width of the conductive via, and theheat spreader has a height smaller than a height of the conductive via;removing the patterned mask; attaching a die to the heat spreader;embedding the die, the conductive via and the heat spreader in a moldingmaterial; forming a first redistribution structure at a first side ofthe molding material; attaching external connectors to contact pads ofthe first redistribution structure; and forming a second redistributionstructure at a second side of the molding material opposing the firstside, wherein the heat spreader is proximate the second side of themolding material, wherein forming the second redistribution structurecomprises forming an opening in the second redistribution structure, theopening exposing the heat spreader.
 20. The method of claim 19, whereinplacing the heat spreader comprises performing a plating process to formthe heat spreader.